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[vsolj-alert 777] SN2000cl



From owner-vsnet-alert@kusastro.kyoto-u.ac.jp Mon May 29 13:51 JST 2000
Date: Mon, 29 May 2000 13:14:29 +0900 (JST)
From: Hitoshi YAMAOKA <yamaoka@rc.kyushu-u.ac.jp>
To: vsnet-alert@kusastro.kyoto-u.ac.jp, isn_chat@supernovae.net,
        astro-l@uwwvax.uww.edu
Cc: yamaoka@rcsvr.rc.kyushu-u.ac.jp, dgreen@cfa.harvard.edu
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Subject: [vsnet-alert 4896] SN 2000cl in NGC 3318
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cf. [vsnet-chat 2994] Apparent SN in Ngc 3318
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/vsnet-chat/msg02994.html
cf. [vsnet-obs 27916] SN 2000cl early photometry from IAUC 7432 and vsnet-chat 2994
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/Mail/obs27000/msg00916.html

Dear SN watchers,

  R. Chassagne, French SN observers and the member of AUDE, has
discovered his 2nd SN in the southern galaxy.  The host galaxy is a
nearby one and the spectrum (type II) and the intrinsic brightness of
this SN suggest that it is peculiar one!  The followups are urged.

  According to IAUC 7432, the discovery was made on May 26.666 when SN
was mag 14.8.  The position of this object is R.A. = 10h37m16s.07,
Decl. = -41o37'47".8 (2000.0), which is 6" east and 7" south of the
center of the tilted spiral (SAB(rs)b) galaxy NGC 3318.  The object
lies on the southern arm.

  Because of low Galactic latitude (b = 14.6), there are several
confusing foreground stars.  Especially, a mag~14 star (27" east and
33" south from the host's core) and a mag~15 star (28" east and 10"
south) are not included USNO-A2.0 catalog.  The discovery image at:
http://vsnet.astrosurf.org/terre/chassagne/SNngc3318.htm will help the
identification.  SN is quite near to the core of the host galaxy.

  The spectrum of SN 2000cl has been obtained at ESO, which shows that
it is of type II event (can be seen at:
http://sc6.sc.eso.org/~lvanzi/sn3318.html) .  However, it seems to me
that it is not a typical type-II event, in opposition to the Maury's
report on IAUC 7432.  The H-alpha, H-beta, He I lines show the narrow
feature.  And, using the NED recession velocity (2770 km/s), the
current absolute magnitude of SN is about -18.2 (with H_0 = 70
km/s/Mpc), which is brighter than the normal type-II SN.  I guess it
is a bright type-IIn event, like SN 1999E or 1998ee.  Note that such a
bright type-IIn SNe are proposed to be related with the GRB events
(like as SN 1997cy), though any GRB has not detected from the
orientation of SN 2000cl these 2 months. The followup observations
are especially encouraged. 

Sincerely Yours,
Hitoshi Yamaoka, Kyushu Univ., Japan
yamaoka@rc.kyushu-u.ac.jp





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